1. Field of the Invention
The invention relates to a capacitor amplifier; in particular, to a capacitor amplifying circuit capable of using a current mirror circuit to achieve a capacitor amplifying function without an operational amplifier and an operating method thereof.
2. Description of the Prior Art
In general, in an analog circuit, a capacitor amplifying circuit is often used to avoid the use of a capacitor having excessive capacitance value to properly reduce the area of the integrated circuit.
Please refer to FIG. 1. FIG. 1 illustrates a schematic diagram of one type of conventional capacitor amplifying circuit. As shown in FIG. 1, the operational amplifier 30 is needed to be additionally disposed in the conventional capacitor amplifying circuit 1 used to compensate the frequency response of the amplifier 20 to make the capacitor 22 having small capacitance value C equivalent to a capacitor having large capacitance characteristics to achieve the capacitance compensation and amplification effect. However, the operational amplifier 30 additionally disposed in the conventional capacitor amplifying circuit 1 will increase cost and make the capacitor amplifying circuit 1 become more complicated.
Therefore, the invention provides a capacitor amplifying circuit and an operating method thereof to solve the above-mentioned problems occurred in the prior arts.